Broaching machine



J. L. PERKINS ET AL B noAcx-IING MACHINEv Filed Feb. 13.l 192,2 Y. 7 Sheets-Slheet 2 1 71M. l fit v,

K ATTORNEY.-

'March .M 1924o 3,436,6@4

lJ. L. PERKINS ET AL BRoAcHING MACHINE Filed Feb'. 13, 1.922 '7 Sheets-Sheet 3 March n 1924, @www J. L. PERKINS ET A!- BROACHING MACHINE Filed Feb. 1s ,A 1.922 v' sheetssheet 4,

' /f/ f 'T f4.7 7K

" f f M6 March 11 1924..

J. L. PERKINS ET AL BROACHING MACHINE Filed Feb. 13 l 1.922

7 Sheets-Sheet 5 A TT ORNE Y.

March l1 ,.192@

Tum

Filed Feb. 13 1922 7 Sheets-Sheet 6 ATTORNEY.

11 1924. www@ 1. L. PERKINS ET AL BROACHING- MACHINE Filed Feb. ll5, 1922 7 Sheets-Sheet '7 ff\ #Armi /fl a2 Y A TTORNEY.

' in their holders, together with manually raaaaa aan n, tera errar JULIAN L..PERKIN S, GF WT SINGFE,

AND E D. CROF', Oli' SPRHQGFD,

JOHN OMLEY, BERT A. WUASN, CHUSETTS, SSIGNQRS TD EMUJS 'TSCHUSETT BROACEIENG EMCHL'NE,

To all ywhom. z't may concern.'

Be it known that we, JULIAN L. PERmNs,

a citizen of the United States of America, and a resident of West Springfield, in the county of Hampden and State of Massachusetts, JOHN OAKLEY, a sub'ect of the ling of England, residing at ringiield, in said count. and State, andA oismrr A. WILSON and IRAM D. Cnor'r, both citizens of the United States of America, and residents of said Springfield, Massachusetts, have invented a new and useful Broaching Machine, of which the following is a specitication.

Our invention relates to improvements in machines for broaching eXteriorly annular or many-sided objects, and more particularly gear blanks to produce gears of a certa-in type, and consists generally and preferably, with a suitable supporting frame, of twin work holders arranged-on opposite sides of the transverse center of the machine, the holders in each pair having an orbital path around a common center, means 'and mechanism for securing the work on said holders, automatic indexing mechanism for said holders, a pair of broach holders having movement in differentdirections, and located between the work holdeis in the two pairs on opposite sides of the aforesaid center, the axes of such broach holders being in the same vertical plane, which plane is in the longitudinal center of the machine and is herein termed the cutting or Work plane, and said work holders being capable of having their axes located normally in said plane, and means for securing the cutters or broaches and pedally-operated means or mechanism for effecting or producing certain operations in the machine, and such other parts or members as may be necessary or desirable in order to render the machine complete and serviceable in every respect, all as hereinafter set forth.

rThis is an upright machine and the principal elements thereof are disposed verticall @ne object of our invention is to produce a machine wherewith a plurality or multiplicity of ring gears, such as those that constitute parts of the starters in Ford automobiles or example, may be cut or breached most expeditiously and at the minimum cost.

further object is to provide, in a machlne of this character, means and mechamsm for cutting simultaneously two sets of gear blanks, 1while at the same time unloadm0 or removing two sets of gears already cu and loading the same number of additional sets of blanks in readiness for breachmg, the unloading and loading operations being performed by the operator.

Another object is to afford means tor making the roughing cuts in the gear blanks on the stroke oi the roughing cutters in one direction, usually the down stroke, and making the finishing cut on the stroke of the tinishing cutters in the opposite direction, usually the up stroke, so that at each complete reciprocation of each broach holder a line of finished gear-tooth slots is cut in the set of blanks being operated on. This is possible because the roughing and finishing cutters or broaches are both set in one holder which has a reciprocable movement and an oscillatory movement about its axis as well, said breaches being received in the periphery of said holder in different radial planes thereof, but generally at the same elevation.

Still another object is to provide such a machine that is automatic inthe broaching and indexing operations, and in which complete and convenient control by hand and operation of certain elements by foot can be eil'ected in a practicable and eiicient manner.

The machine is equipped with all necessary locking devices .for movable and adjustable elements, to the end that improper movement at improper times is prevented,

and the machine is rendered safe and rb.-

liable as well ashighly efficient.

Other objects and advantages will appear in the course of the following description.

A preferred embodiment of the invention, whereby we attain the objects and secure the advantages of' the same, is illustrated in the accompanying drawings, and we will proceed to describe the invention with reference to said drawin although itis,- to be understood that the torm, construction, ar-v rangement, eto. of the parts in various aspects are not material, and may be moditied ence characters Fig. 4, an end elevationr of said mechine,-

with a rtion ofthe carrier therein appearing broken out to show features that would otherwise be hidden; Fig. 5, an enlar d detail of one of the movable dogs assoclated with or forming a part of the osn cillatory mechanism for each broach holder; Fig. 6, a side elevation of the switch-operating mechanism through the medium .of which the electric motor (not shown) that drives the broach carriers is reversed; Fig. 7, a detail of the left-hand broach carrier and holder, with the supporting members :for said carrier, the parts and members being viewed as in Fig. 4, except that said carrier with said holder is at the lower end of its travel in Fig. 7 instead of at the upper end of its travel as in Fig. 4 and other views; Fig. 8, an enlarged, cross section through one of the broach holders; Fig. 9, a similar section taken at a different elevation from the immediately preceding section; Fig. 10, an enlarged, top plan of a portion of the operating mechanism for one of the broachholder lock pins; Fig. 11 and 11a together constitute an enlarged, vertical section through said left-hand half of the machine, in approximately the vertical, longitudinal center or work plane thereof; Fig 12 is an enlarged, to plan of the index or indexing mechanism or one of the Work holders; Fig. 13, an enlarged, top plan of, the left-hand, manually-operated and pedally-operated lever mechanism, with which the machine is euipped; Fig. 14, an enlarged, bottom plan o a portion of the base of the frame of the machine, showing the pivots and their bearing lugs for certain of the elements in the aforesaid mechanism, together with the rockshaft of such mechanism; Fig. 15, an en-` larged detail of the rock-shaft lock member;

Fig. 16, a side elevation of said mechanism as shown in Fig. 13; Fig. 17, a top plan of the lock segment for one of the work holders; Fig. 18, an enlarged, operative detail of the locking means Jfor theY left-hand broach holder, and, Fig. 19, a similar detail but showing the parts and members differently dis sed. I

` e cutting or work plane hereinbefore referred-to is on lines y'y in Fig. 1.

This is adouble or duplex machine throughout, and the mechanism on either side of the transverse center of said machine is complete in itself or forms a complete unit. The double construction is preferred and used for the sake of economy in building the machine, the compensation or balance obtainable with the breaches when in operation, and the saving in door space and power. A lar saving in floor space is also effected by ma in a vertical or u 'right instead of a horizonte machine. It fo lows that one side of the machine lis practically a duplicate of the other side, and that one end of said machine is practically a duplicate of the other end. In View of the conditions just mentioned, it has been deemed necessa to illustrate in detail generali but onealf of the machine, the left-han half being the one selected. The term left-hand is to be understood as applying to the machine as viewed in Figs. 1 and 3, wherein the ends of the machine are respectively disposed at the left and right of the transverse, vertical, central plane of the machine. Nevertheless, certain central elements that enter into the construction of the left-hand portion of the machine must extend to the right of the aforesaid transverse plane.

In the drawings, the left-hand broach holder is shown at the upper end of its stroke and the right-hand broach holder at the lower end of its stroke, except in the example noted, namely, Fig. 7 and the other elements generally are normally disposed.

The frame of the present machine comprisesa base 1 which is designed to rest on the floor, and two uprights 2 having forwardly and rearwardly-extending bottom, plate extensions or flan es 3,-3 which are mounted on said base intermediate of its ends and securely bolted thereto, said uprights bein connected at the top by a member 4, an having exterior and interior strengthening webs substantially as shown. Some of these webs will subsequently receive special mention. The u rights 2 extend below the ioor line, and ocated under said uprights is a funnel-shaped receptacle 5. The receptacle 5 is open at the top, and this opening is considerably larger in diameterr than the space occupied by the depending portions of the uprights 2. The waste oil used to lubricate the parts between the uprights 2 passes downwardly into the re-` 'ceptacle 5, and so also do the chips produced by the cutting operation and the oil used in connection with such operation. The frame also comprises bearing parts and other members of which particular mention will be made when necessary at this description progresses.

For the sake of convenience in describing the machine, and as alread intimated, the side illustrated in Fig. 3 will be considered as the front and the opposite side as the rear.

large gear 1t,

dournaled in the nprights' 2 'and in suit able bearings with which said uprights are provided, in the transverse central lane of the machine, one above the other in the order named, and beginning a short distance above the horizontal plane or the danos 3, are three horizontal shafts 6, 7, and 8, igs. 1, 3, and t. Secured on the forward protruding terminal ofthe shaft '6 is a ear 9. .This ar is designed to be driven Jrom a motor, and a motor pinion or gear 10 and a tragment et a motor shaft 11. are represented in Figs. 1 and 6 but omitted from Fig.4 3, said motor gear intermeshing with said tirstnamed gear. Secured on the rear protruding terminal of the shaft 6 is a pinion 12, and this intermeshes with a gear 13 secured on the rear protruding terminal of the shaft Secured on the center of the shaft 8 is a and intermeshing with said gear is a small gear 15 which is secured on the' shaft 7, Fig. 11a. that motion imparted pinion 10 is transmitted, 6, and the pinion 12, the and the gear 15, to the ld causes the cutting or breaching elements to reciprocate, as explained below.

ere is a vertical broach carrier 16 arranged to slide up and down in contact with each pair of outer edges of the 1uprights 2, said carrier being to the gear 9 by the through the shaft gear 13, the shaft gear 14. The gear provided adjaccint to its outer (front and rear.) edges on the inside.

faces thereof with a pair of V-shaped pro` jections or guides 17 that enter and operate in corresponding grooves in the contiguous edges of F ig. 2. The carrier 16 is held in place relative to they uprights 2 by means of a pair of vertical gibs 18 bolted to said uprights, *all U in the usual and well-known manner@ @n the inside of the carrier 16 in the transverse center thereof is a rack 19, and the ear 14C intermeshes with such rack. -There ing a rack 19 at each end of the horizontal diam-f' eter of the gear 1t, the two racks and their* carriers 16 are actuated in, opposite direcv gear is rotated. lfVhenfthe tions when said gear 1t is rotated in the directlon of the'v associated arrowinfFig.- 11, the left-handcar# rier 16 is actuated downwardly and .the right-hand carrier 16 is actuatedupwardly, and, when said gear is rotated in site direction, said :Erst-named carrier is actuated upwardly and said second-.namedc'arf rier is actuated downwardly. Ubvio'usly means must be provided for reversing the.:` vgear 14, and such means consists of the cus- V switch and switchop'ere' ating mechanism whereby the motor anditsf..

ternary, automatic,

shaft 11, which drive the gear 14 and the racks 19 with the carriers 16, are actuated hrst in one direction and then in the opposite'- direction, said switch and mechanism oper! ating in the'usua'l and well-known manner.

ieaaeoe l lt follows, therefore,`

said uprights, as best shown in.

Vwhereby of theparts controlled thereby, such action taking' placeby the time the carrier in queslongitudilvlal its outer vface,

the oppo- @2, t', 'Z and 11.- .The holder 26 l' top and` bottom, fnaled lin suitable the ends of said The switch-operatin mechanism comprises a switch-box 20 astened to the bach side of the rear uright 2, a switch-arm 2l projecting trom te bottom of said box, a pinion 22 secu-red to thev shaft 8, which latr carries the gear 1t and extends behind said rear upright, and a gear 23 loosely mounted on a horizontal stud 2d that projects trom said rear upright above said shaft and between the lsame and said box, said lastnamed gear being provided with adjustable dogs 25-25, Figs. 1 and 6. This switchn operating' mechanism is so timed that, when one of the carriers 16 arrives at the lower end oi its travel, one of the dogs 25 encounters the switch-arm 21 and actuates the same to throw the electric switch (not shown) in the switch box 20 in the directionto cause the motor shaft 11 to be rotated in the/opposite direction, and, when the other of said carriers arrives at the lower end of its travel, the other dog 25 encounters said switch-arm from the opposite side and actuates the same to throw said switch for the reversal again of said shaft. Ait the time either carrier is at the lower end of its travel the other carrier is at the upper end of its travel. llVith the parts disposed as in Figs. 6 and 11, and the gear 14 revolving in the direction of the associated arrow in the latter view,

gear, and so causes rection, consequently the right-hand dog 25 lencounters the switch-arm 21 and throws thev same to the left, whereby is brought about the reversal of the parts controlled thereby,

by the time the carrier shown in Fig. 11 varrives at the lower end of its travel. pon the reversal of the revolving members, the left-hand dog 25 encounters the switcharm 21 and throws the same to the ri ht, or

into the position which it occupies in tig. 6, is brought about another reversal tion arrives at the. upper end of its travel.

'Eachbroac-h carrier 16 is provided in the center of what may be termed yor in the side opposite to that whereonone of the racks 19 is located,

.with acylin'drical breach holder 26, the latter havingY approximately one-half of its circumference let-into an `approximately semi-icylindrical openingin the former, Figs. is yvertical like its carrier, and. has. trunnions27-.27 at the which trunnions are jour- 'bearing-boxes formed at carrier, and completed by upper and lower bearing-caps 28-28 securedV by jscrews to said carrier. 'l`hus mountedthe holder 26 is capable ot being oscillated on its vertical anis. The oscillatory movement of lthe holder is produced pposite dillO throu h the medium of apair ofhorizontal, paral el racks 29 slidingly arranged on .the same plane in the carrier 16 a short distance below the upper bearing-cap 28, teeth formin segmental gears 30.--30 cut diametrica ly opposite to each other in the (periphery of the holder 26, and up er an lower cam segements 31 having teet 31a on their arcuate edges, loosely mounted on horizontal studs 32-32 t-hat project inwardly fronthe uprights 2 on the same side of upper and under, intermediate webs 33 and 34 which connect said uprights respectively above and below the gear 14, together with locking and actuating pinions or gears 35-35 mounted on horizontal rockshafts 36-36 journaled, above and below said studs, in said uprights and projecting beyond the back side of the rear upright-see more particularly Figs. 13 and 16. The rock-shafts 36 at the right of the webs 33 and 34 project beyond the face of the front upright 2. The racks 29 are on opposite sides of the holder 26, and tangentialthereto. As shown in Fig. 16 the upper segment 31 is arranged with the teeth 31L above, andthe lower segment 31 with the teeth 31a below. The edges of the segments 31 which are adjacent to the holder 26 are cam edges and designated by the numeral 37 in each case. The segment teeth 31* intermesh with the pinions 35. The pinions 35 are held rigidly, by means hereinafter described, and in turn retain the segments 31 in fixed positions with their cam edges 37 in the paths of the inner terminals of the racks 29, such edge of the upper segment inclining upwardly and outwardly, and such edge of the' lower sector inclining downwardly and outwardly, from the studs or pivots 32. lnasmuch as the racks 29 are on opposite sides of the holder 26, the Segments 31 must-be correspondingly disposed in the space between the uprights 2. The upper segment 31 is in the same vertical plane with the rear rack 29, and the lower segment 31 is in the same vertical plane withI the front rack 29.

lt is now clear, that, when the carrier 16 approaches the lower end of its travel, the inner end of the front rack 29 encounters the edge 37 of the lower segment 31, and is forced outwardly or to the left by such edge. This action causes the holder 26 to be partially rotated to the right in the carrier 16, inasmuch as the front rack 29 is in engagement with the forward segmental gear 30,

to an extent corresponding to the length of travel of said rack. At the same time the rear rack 29 is actuated inwardly by the other segmental gear 30 with which said rack intermeshes, so that the latter is in position to encounter the upper segment 31 when the carrier 16 approaches the upper end of its travel. Upon the ascent, therefore, of the carrier 16, the inner end of the rear rack 29 .come apparent.

contacts witlrthe edge37 of the upper sector.31,"andls'aid.rack is forced outwardly lby said ed el' The outwardzmovementpof. the rear rac ,A causes the carrier, 26 tobe'partially rotated to the left to.the...same extent that 1t had been previously rotated' to the right by the front rack-29, and the latter to be actuated inwardly again. ."It is seen, therefore, that the left-hand holder 26 has .imparted to it approximately a quarter-turn to the right each time it arrives at-'the end of they down stroke, and a quarter-turn tothe left each time it arrives at the-end of the up Stoke, the reason for which will subsequently be- The amount of' rotary movement of the holder naturally depends on the piro rtions of the segmental gears 30 and t e ength of stroke im arted by the segments 31 to the racks 29. (gne-fourth of a revolution is here provided for.

The construction and arrangement of the oscillatory mechanism for the ri ht-hand holder 26 are such as to cause said older to operate or to be operated on its axis in a similar manner as is the left-hand holder.

It is necessary to lock each holder 26 against rotation at the end of every quarterturn thereof, and for this purpose a horizontal segment 38 is mounted on the top of the upper trunnion 27 of said holder and rigidly secured thereto, said segmenthaving three openin s 39 -therein arranged in an arc which 1s concentric with the arc of the segment, a vertical pin 40 slidingly arranged in the head of the carrier 16 for said holder, a yoke 41 at the inner end of an approximately horizontal arm 42 which is secured to the inner terminal of a horizontal rock-shaft 43 journaled in the head of said carrier, a depending arm 44 Secured to the outer terminal of said shaft, said last-named arm being provided on the front side at its free terminal with a roll'45, and two movable dogs or cams 46 pivotally connected at 47-47' with plates 56-56 secured to the gib 18 on the left-hand edge of the rear upright 2 see Figs. 1, 3, 4, 5, 7, 10, 11, 18, and 19. The axis of the pin 40 is directly over the arc in which the openings 39 in the segment 38 are located, so that the lower terminallof said pin is adapted to enter any one of said openings. lUpper and under bushed bearings 48 and 49, respectively, are provided, in the upper part of the carrier 16 for the pin 40, and said part is cut away beneath the under bearing, as represented at 50, to accommodate the inner or arcuate portion of the circling said pin between said collar vand the bearing 48. The spring` has a constant tendency to torce the pin 41 downwardly onto' the segment 38, or to retain the lower terminal ot said pin in one of the openings 39, said spring acting directly on the lian e 52 and forcing the same downwardly ont e olle 41 and the latter onto the top of the caring 49. 'When the segment 38 is disposed to receive the. lower terminal of the 'pin 40 in either of the end openings 39 in said segment, the holder 26 is positioned in one or the other ot the extreme positions of its oscillatory movement, and, when 'such segment is disposed to receive such terminal in the intermediate opening 39, said holder is positioned at a point intermediate ot the limits ot its oscillatory movement, or in neutral position, all due to the relative relation ont the segment to the holder. 'lhus the pin 40 locks the segment 38 and the holder 26 in any one of the three positions.

The arm 42 of the yoke 41 extends reariwardly in the upper part of the carrier 16 to the rock-shalt 43. The rock-shaft 43 is journaled in a bearing 54 that projects toV the left from the aforesaid part or" the carrier. An opening 55, Figs. 4, 18, and 19, is provided in said part to accommodate the arm 42 and permit the same to be operated. The openings 51 and 55 are in communication with each other. The arm 44 has a normally downward and rearward inclination, and the cams 46 are in the path g of the roll 45 with which said arm is provided. 'lhere are two of the cams 46 on a side for each arm '44, of which latter there are two inthe machine, and such cams are located one above the other in position to be encountered by the roll 45 just before the carrier 16 arrives at the upper and lower ends ot its travel, respectively.

Each cam 46 is a member bent intermediate of its ends to form an obtuse angle, and is loosely mounted on one ot the pivots 47. Each pivot 47 extends outwardly from one of the plates 56. The plates 56 extend forward beyond the edge of the gib 18 to which said plates are attached, and it is in the projecting parts of said plates that the pivots 47 are set. ln the present construction, the plates 56 for the right-hand pivot 47 are fastened to the front forward gib 18 at the right-hand end of the front upright 2. 1n each case the upper cam 46 depends from its pivot 47, and the lower cam 46 extends upwardly from its pivot 47. A stop pin 57 is set in each plate 56 in position to limit the outward or rearward movement of the free terminal of the adjacent cam 46. consideration being given again to the left-hand cams only. A spring 58 is provided for each cam 46, and said spring has one terminal fastene to the pivot 47 for said cam, and the opposite terminal arthe cam. Th

ranged to bear against the inner side or e spring 58 serves to actuate the cam toward the associated pin 57, and normally retain the former in contact with the latter.

When the carrier 16 descends, the roll 45 rides onto the inclined part of the lower cam46, as said carrier vapproaches the lower end of its travel, and is conse uently carried forwardly or inwardly by said cam and onto the vertical part of the same, and the arm 44 that is provided with said roll is thereby swung inwardly on its pivot 47, and imparts a partial rotation to the rock-shaft 43 in the direction to swing upwardly the arm 42-see full lines in lenig. 18. The arm 42, through the medium ot its yoke 41 which bears against the under side ot the flange 52, in movin upwardly with the arm 42, carries with 1t said flange and thus raises the pin 40, against the resiliency of the spring 53. rl`he pin 40 is raised suiiciently to withdraw it from the segment 38. The segment 38 being 40, is Jtree to move on its axis and so leaves the holder 26 free 'for the partial rotation directly imparted to it by the front rack 29. By the time the carrier 16 reaches the extreme end of its downward movement, the roll 45 is in position to pass beneath the bottom of the lower cam 46, and the spring 43 immediately acts to depress the in 40 and thrust the same into the opening 89 in the segment 38 that is the most remote from the opening 39 in which said pin .was previously located, so that said segment and the holder 26 are again locked against rotation. When the carrier 16 ascends, the roll 45 is carried upwardly on the outside of the lower cam 46 as indicated by brolren lines in l? ig. 19, andthe latter swings inwardly to enable Said roll to continue its upward movement 4and pass clear of said cam, the spring 58 for said cam yielding to permit of such action and then causing the cam to snap back into contact with its associated pin 57 as soon as the roll clears the cam. Next, as the carrier 16 approaches the upper end of its travel, the

roll 45 encounters the inclined portion of the upper cam 46 and rides onto the vertical part of said cam` as illustrated in full lines in Fig. 19, and the pin 40 is again withdrawn to release the segment 48 and the holder 26 in precisely the same manner as before, when the rear rack 29 is caused to act partially to rotate said holder until it assumes its former position. rlhen the roll 4'5 passes over the top of the upper cam 46, and the pin 40 descends again into loclring position to secure the holder 26 against thus released from the pin rotary movement. Upon the descent of the t carrier the second time, the roll 45 ridesl down on the outer side of the upper cam 46, as represented by broken lines in Fig.

18, and forces the same out of the way, against the resiliency of the spring 58 that is provided for said cam, until said r'oll clears said cam, when the latter snaps back into contact with the adjacent pin 57. The roll 45 sets out far enough to clear'the ends of the springs 58 that engage the cams 46 contacted with by said roll.

I will next describe the mechanism by means of which the pinions 35 are held stationary, and through the medium of which said pinions may be actuated to throw the segments 31 into neutral position, or into position to cause the holder 26 controlled thereby to be disposed in neutral position. Such mechanism comprises certain connecting-rods and operating levers, and is connected with other connecting-rods and operating levers which are associated with the work-holding mechanism of the machine.

Referring more particularly to Figs. 13 and 16, it will be seen that the rock-shafts 36, upon which are mounted the two gears 35 that control the sectors 31 by means of which the racks 29 that engage the lefthand holder 26 are operated, are provided on their rear terminals, which terminals extend beyond the back upright 2, with arms 59 and 60, the first of these arms being carried by the upper rock-shaft and the second by the lower rock-shaft. The arm 59 extends downwardly to the right from thel upper rock-shaft, and the arm 60 extends downwardl to the left from the lower rock-shaft. connecting-rod 61 has each end pivotally attached at 62 to the arms 59 and 60, the upper terminal of said rod being connected with the free terminal of said first-named arm, and the lower ter- 'minal of said rod being connected with said second-named arm intermediate of its ends. The construction and arrangement of the parts are such that, if the connecting-rod 61 be raised, the arms 59 and 60 are swung upwardly so as to carry the (pivots 62 through ycorresponding arcs an actuate each rock-shaft 36 to the same extent that the other rock-shaft is actuated, and to actuate said rock-shaft and the gears 35 in opposite directions. The upper gear 35 is actuated to the leftand thelower gear 35 to the right, with the result that the segments 31 are swung to the right or inwardly on their pivots 32. When the sectors 31 are thus inwardly disposed, by elevating the connecting-rod 61, whichever of the racks 29 contacts with its associated segment is actuated to the left or outwardly only far enough to impart to the holder 26, with which said racl'. is in engagement, a rotary movement the extent of which is about onehalf of that normally imparted to said holder by the rack. In this manner and by this means the holder is caused to assume an inactive or neutral position, the reason for which will hereinafter be made manifest. The movement which the .gears 35 impart to the sectors 31 is not sufficient to remove the cam edges 37 of said sectors entirely from the paths of the racks 29, but enough to reduce to the required extent thel travel imparted to said racks by said edges. Upon actuating the connecting-rod 61 downwardly into its former position, the arms 59 and 60 and the parts and members operated thereby are returned to normal positlon.

Normally, the near rack 29 moves from the dotted-line position to the full-line position shown in Fig. 16, as said rack moves or is carried upwardly, and a similar action occurs when the front rack 29 encounters the lower segment 31, in the downward movement of said front rack. These movements are cut down or shortened when the segments 31 are swungl inwardly so as to project less into'the paths of the racks, or so as to present to said racks cam surfaces which are more nearly erect.

Each of the connecting-rods 61 is raised and lowered by means of a manually-operated lever 63 which is pivotally connected at 64 either with the oblique web (188) that extends rearwardly and to the left from the back upright 2, or with the oblique web (189) that extends forwardly and to the right from the front upright 2. The pivot 64, for the lever 63 that operates the connecting-rod 61 associated with the left-hand holder 26, is set in the web 188, while the other pivot 64 is set in the web 189. Each of the aforesaid webs is provided with a sector 65 in vwhich there are two radial openings 66, as shown in Fig. 16. The inner terminal of each lever 63 is forked as shown at 67, and such terminal embraces the associated connecting-rod 61 between two anges 68 thereon. Sad lever is provided with a latch-rod 69, adapted at its inner terminal to entereither of the openings 66 in the sector 65. A keeper 70 is provided on the lever 63, adjacent to the sector 65, to serve as a guide for thel latch-rod 69. At the outer end of the lever A63 is a. handle 190. The outer end of the latch-rod 69 is connected with a latch 71 which is pivotally connected at 72 with the lever 63, adjacent to the handle 190. The latch 71 is extended outwardly alongside ofl the handle 190, and a spring 73 is interposed between the extendedy part of the latch and said handle, so that said part is normally held away from said handle, and the rod 69 permitted to enter into locking engagement with the sector 65.

When the inner end of the latch-rod 69 is in the upper opening 66, the connecting-rod 61 is thereby locked in its low position, in which position the parts are disposed and held in such a way as to present the cam edges 37 of the segments 31 at their sharpest treason incline to the racks 29. Before the connecting-rod 61 can be raised for the purpose of throwing the holder 26 controlled thereby into neutral position, it is necessary to grasp thehandle 190 with the extended of the latch 71, and force such part, against the resiliency of the spring 73, toward said handle, whereby said latch is rocked and the latch-rod 69 drawn out of the upper openlng 66.- rlhe lever 63 can now be rocked on its pivot 6dto raise the terminal 67 thereof and with it the connecting-rod 61. After thus elevating the connecting-rod 61, the letch'71 is released to its spring A73, and the latter acts to return said latch to normal position and actuate the latch-rod into the lower openingj66. rlhe lever V63jis now locked in its new position, and with .it the connecting-rod 61 in elevated position, and the holder 26, as the same is moved up and down by the carrier 16 provided therefor, remains in neutral position. ll on again grasping the handle 190 and withdrawing the latch-rod 69 from the lower opening 66, and rocking the lever 63 downwardly at the forked end, Ito lower the connecting-rod 6l and permit said latch-rod to enter the upper opening 66, 'the parts and -members are again disposed irl-such a manner that the holder 26 is oscillated to the full extent by the racks 29.

A bell-crank-lever 7d is pivotally attached at to the back side of an intermediate wall of the base 1, below the horizontal plane of the free terminal oit the arm 60 above, at the lett of the transverse, vertical, central plane el said base, and another bellcranlelever 7/1- is similarlyy attached to the front of said wall below the horizontal plane of the tree terminal of the other arm 60, at the right ci said vertical lane, Figs. 3, 13, and 16. A connecting-roV 76 has its upper terminal pivotally attached at 77 to the tree end of the arm 60 above, and its lower terminal pivotally attachedv at 77 to the inner terminal of the associated bell-crank-lever, there being` such a rodbetween each arm 60 and the bell-cr-lever` "below The s bells fouter terminal with a angles uppermost, and the anig'ular portion of each is the partA mountedon thefpivot 75 provided for the same. 'lhereisahorizontal bearing 78 for eachfpifvot-75, which.hearingV extends from the aforesaid'intermediate.wallof the base, such wall being. indicated v'by the 'OOk-fsheft SOfS ztreadleadjacent to numeral 79. A transverse journaled in bearings 81 'and 182 in"` c portion of the base 1, as fsliownji All,lli-g. y Secured to the outer endorterminalfof each of these rock-shafts is an upstandin'g-arm- 83, and a connecting-rod Y84Y extends-between said arm and the short alan-oll theadjacent bell-crank-lever 7 4f, suchbell-crank-lever being arranged in each casewithits short arm extending' toward the adjacent) end'` lot' theV vthe inside; and

base 1 and its long arm extending toward the central, transverse, vertical plane o said base. Each connectin -rod 8d is approxirrnatelyv horizontal an has its ends pivoted at 8585 to the contiguous arno 88 and the short arm or the contiguous beilcranlr-lever, respectively., llach roch-shaft has an otfset 86 therein, the transverse center or which is in the 'worlr plane g/-fz/ of the machine.

The roch-shalt 86 and its connections for cach end or the machine, are so arranged that, when the associated connectin -rod 61 is in its depressed and normal position, the associated connecting-rod 76 is also in depressed osition, and the oliset 86 is disposed vertically. Upon elevating the connecting-rod 61 and, througlrthe medium o the arm 69, the connecting-rod 76, the bellcranlr-lever 7d is actuated to draw inwardly the connectin -rod 84, and thus partially to rotate the roc -shat 80 in the direction to carry the offset 86 ;trom the vertical into an approximately horizontal position. A versal of the movement of the connecting-rod 61 brings about a reverse movement of the intervening parts and members'between said rod and the roch-shaft 80, and actuates the latter in such a manner as to return the odset 86 to vertical position. rllhe offset 86 serves as a loclr for a pin 87 that will subsequently be described.

Associated with the connecting-rod 8land the rock-shaft 89 in each end of the hase 1, although not directly connected therewith, are an approximately horizontal treadie 88, and two approximately horizontal levers 89 and 99. The treadle 88 is pivotally connected at 9i, intermediate or? its ends, with a pair of lugs 92 with which each end portion or the base is provided on the inside; the lever 89 is pivotally connected at 93 with a pair of lugs 9d with which said end portion is also provided on the lever 90 has its inner end pivotally connected at 95 with a pair of lugs 96 with which said end portion is further provided. Each treadle 88 extends outwardly through a slot in the adjacent is provided at its loot-piece 97. The outer end of the lever 89 has an universalor ball-joint connection 98 with the inner ondof the treadle 88, and an universalor ball-joint connection 99 is provided between thepouter end of the lever 90 and said the pivot 91 and between fsaid pivot and said first-named ball-joint connection. rlhe inner terminal oiE the lever 89is vforked, as shown at 100. The lever 90,. is provided on top adjacent to the pivot, 95 with a disk or plate 101 tutes what may be termed a stirrup. 'lhe treadle mechanisms and the rochshafts 80 with their offsets 86 are associated which constiwith work-holding mechanisms that are' mounted on the base 1 at both ends above said first-named mechanisms and said rockshafts. The purpose and operation of the treadle mechanisms and the rock-shafts 80 will, therefore, be left for consideration in connection with the work-holdingvmechanisms.

Referring nent more particularly to Figs. 2, 4, 8, 9, and 11, it will be seen that the broach-holder 26 therein shown has a large, longitudinal recess or opening 102 in one side thereof, and that such opening is adapted to receive a pair of vertical L-shaped bars 103, and a -plurality of horizontal lock blocks 104. Each bar 103 has a broad arm and a narrow arm. One of the bars 103 carries a plurality of roughing cutters or broaches 105 and the other of said bars 103 carries a ,plurality of finishing Cutters or broaches 106` there being in the present y example four of each.

. carried by the bar.

at the inner end of each recess 110 to afford The roughing broaches 105 are positioned to cut on their down stroke. and arranged with one face of each against the broad arm of one of the bars 103, and with their inner edges against the narrow arm of the bar, and are initially secured to said bar by means of screws, such as those shown at 107 in Fig. 9. Each screw 107 is introduced into an oblique recess 108 in the outside of the bar 103, and tapped into one of the broaches, sufiicient stock being left at the inner end of said recess to aiiord ample support for said screw. There may be provided three, more or less, screws 107 for each broach 105. I

The finishing broaches 106 are positioned to cut on their up stroke, and set into and secured to the other bar 103 in substantially the same mannervand by substantially the same means as have been described in connection with the roughing broaches 105.

The bars 103 are arranged in the opening 102 with the roughing and finishing broaches (105 and 106) adjacent to each other, the outer sides of the broad arms of said bars bearing against the approximately radial sides of said opening, and the innermost surfaces of said bars or of the short arms thereof bearing against suitably cut surfaces in the innermost part of said opening substantially as shown. Thus each bar 103 bears `with two surfaces on the holder 26. Screws, such as those appearing at 109, are employed to assist in holding the bars 10.3 in the positions just described,

and the broaches in place in said bars. Each screw 109 is introduced into a recess 110 that opens through the periphery of the holder 26, and tapped into and through the adjacent bar into one of the broaches Sufiicient stock is left ample support for the screw 109 `located in such recess, and said screw enters the bar 103 and the broach at right-angles thereto.

The lock-blocks 104 afford additional means for retaining the broaches 105 and 106 in place in their bars 103 and the latter in place in the holder 26. There may be any required number of these blocks-in the present case there are five of the same, and these are located one adjacent to the upper ends of the upper broaches, another adjacent to the lower ends of the lower broaches, and the others across the joints between said broaches. Each block -104 is secured in place by means of a bolt 111 which passes through said block and the space between the same and the transverse side of the opening 102, to be tapped into the holder 26, said bolt being radial to said holder. Nhen the bolt is in lace and tightened, it forces its block 104 tightly between the roughing and finishing broaches'with which the ends of said block contact, and thus wedges said block in place and securely holds said broaches and their bars 103 in the holder 26, supplementing the screws 109 and 107. It is necessary that the roughing and finishing broaches be secured so firmly in the holder that there can be absolutelyT no independent movement of said broaches, and to this end the fastening and securing means described above have been provided.

The size of the opening 102 in the carrier 26, and the size, construction, and arrangement of the bars 103 and the broaches 105 and 106 are such that, when said holder is located at either end of its maximum rotary movement, either the roughing broaches or the finishing broaches are located with the central, longitudinal, vertical plane common thereto in the work plane y-y, so that normally either the roughing broaches or the finishing broaches are in said work plane. The aforesaid plane of either set of broaches is also radial to the holder.

The securing means for the broaches in the right-hand holder 26 are precisely the same as those for the broaches in the lefthand holder 26, which latter have been fully described.

The roughing broaches 105 do their work on the down stroke of each of the holders 26, and the finishing ybroaches 106 do their work on the up stroke of each of said holders. The carriers 16 for said holders constantly travel in opposite directions, and, under the present arrangement, when the roughing broaches carried by one holder are making their cut the finishing broaches carried by the other holder are making their cut, and vice versa. This is made possible by locating the two upper segments Y31 in the paths of the two rearracks 29 and the two lower se ments 31 in the paths of the two front rac s 29,because by so doing both holders 26 are actuated in the same direction upon arriving at either end of their stroke, it being understood that, when the roughing broaches carried by one holder are in the work plane, the linishing broaches carried by the other holder are in the same plane, while the inactive finishing broaches are in front of said plane and the inactive roughing broaches are behind said plane, and the reverse is true When the holders are shifted*see Fig. 1. y

rlhe cutting edges or teeth of all of the broaches project beyond the periphery of the holder '26 and beyond the outer ends of the bars 103.

It will now be seen that, when the machine is in' operation, one set of roughing broaches and one set of finishing broaches are constantly in the work plane, and that at the end of each simultaneous up and down stroke of the carriers 16 the holders 26 are shifted to take out of said plane the sets of broaches which have just completed their cutting operation and to move into said plane the other sets of broaches. EX- cept for the instant at the ends of the travel of the carriers 16, when the holders 26 are shifted on their axes and said carriers reversed, one set of roughing broaches and one set of finishing broaches are in the work plane and making their cuts, provided there is work in position at each end of the man chine to be operated on by said broaches.

There are two supporting and carryin elements for the work at each end of the machine, and provision is made for transposing the positions of the same so that either can be located in operative position relative to the adjacent holder 26. We will now describe the aforesaid elements at the left-hand end of the machine, with the understanding that corresponding elements are provided at the right-hand end. Special reference is to be had to Figs. 1, 2,' 3, 4, and 11 and 11B.

A normally-stationary turn-table 112 is mounted on the base 1. rlhe turn-table has a central, vertical shaft 113 which is journaled directlyabove the stirrup 101 located in said base at the left-hand end thereof, in a bearing 114 in the base 1, a ball-.bearing 115 being interposed between saidfstirrup and the bottom of saidV shaft. The portion of the shaft 113 that is inthe bearlng 114 is larger than the portion of said shaft upon which the turn-table 112 is directly mounted, so that a shoulder 116 is formed on said shaft.v Normally the turn-table 112 rests directly on top of the base 1, and the shoulv der 116 is then in the same plane with said top. The axis of the shaft 113 is in the` work plane ofthe machine. The turn-table may or may not be rigidly attached to the shaft 113, just as is preferred.

Rising from the turn-table 112, on opposite sides of the shaft 113, are two vertical shafts 117. Each shaft 117 has a screwthreaded base with which a nut 118 is connected to anchor said base in the turn-table.

Within the aforesaid base of each of the shafts 117 in the axial center thereof is an opening 119. The opening 119 in either shaft is adapted to receive the upper terminal of the lock pin 87. en either shaft 117 is engaged by the pin 87, such shaft and its companion are located with their axes in the work plane y-y. The pin 87 is in position to engage the inner shaft 117, which is the shaft upon which the holder for'the work actually being operated on is mounted, or is a part of such holder.

The pin 87 is slidingly arran ed in a hollow member 120 that depends rom the top of the base 1 in the work plane y-y, and to the right of the bearing 114: or between such bearing and the transverse, central, vertical plane of the machine. The pin 87 is provided with a stem 121 that extends downwardly from the bottom of said pin and through the bottom of the member 120, there being a head122 on the lower end of said stem.v A spring 123 is interposed between the bottom of the pin 87 and the bottom of the main passage in the member 120 and normally actuates said pin upwardly and retains it in engagement with the shaft 117 above. The rock-shaft 80 is so located that, when its oset 86 is vertically disposed, the

g same is directly beneath the head 122 of the stem 121, so that said stem and the pin 87 can not be forced downwardly. The fork 100 of the lever 89 engages the stem 121 above the head 122.

ln order to rotate the turn-table 112 about its axis, for the purpose of changing the relative positions of the work lho ders of which the shafts 117 constitute parts, or, in other words, to interchange the positions of said shafts, it is'first necessary to unlock said turn-table by withdrawing the pin 87 from the opening 119 in the right-hand shaft, and then raise said turn-table with the work holders on the shoulder 116 from the basel. These results are accomplished by graspinOi the handle of the associated lever 63 and actuating said lever to withdraw the o'set 86 from beneath the head 122, and placin the foot on the part 97 of the treadle 88 an actuating said treadle to rock upwardly the connected terminals of the levers `39 and 90. Since the connectionv 98fis. farther from the ivot 91 than is the connection 99, and the ulcrum of the lever 89 is nearer said connection 98 than is the fulcrum of the lever 90, the forked terminal 100 of said lever 89 moves more quickly and through a greater s ace thanv docs the stirrup 101 which is on t e lever 90 quite near to the inner fulcrumed terminal of the same, when the portion of said' treadle withwhich said'levere 130' are connected is elevated. Consequently the lirst effect of the depression of the outer terminal of the treadle 88 is to rockA the lever 89 .in such a manner as to carry the fork 100 thereof downwardly and so withdraw the pin 87 from engagement with the shaft 117 above, through the medium of the head 122 and the stem 121, and against the resistance of the spring 123, which action is possible because the offset 86 is now out of the way of said head. And the second eiect of the motion imparted to the treadle is to raise the lever 90 and the stirrup 101. The upwardA movement of the stirrup 101 is transmitted through the ball-bearing 115 to the shaft 113, and the latter is elevated and carries up with it the turn-table 112 and all of the parts and members supported thereby. The upward movement of the shaft 113 is comparatively slight, being only suicient to raise the turn-table 112 c ear of the top of the base 1. With the turn-table thus elevated the same can be rotated on and with the shaft 113 on the ball-bearing 115.

The same movement of the lever 63 which actuated the offset 86 out of the perpendicular, also caused the left-hand holder 26 to be actuated .into neutral position, with the roughingland linishing broaches carried by said holder disposed on opposite sides of the work plane y-y. Although the lever 63 can be operated at any time, the holder 26 is not actuated into full neutral position until it arrives at one end or the other of its verticalr travel. the holder can continue to move up and down withoutv the broaches contacting with Ithe Work.-

After the turn-table 112 has been given by hand a half revolution, the treadle 88 is released, and said turn-table settles down again by gravity onto the base 1, and the spring 123 forces the pin 87 upwardly into the opening `119 in the base of the newly- `presented shaft .117. The lever 63 is then operated to restore the offset 86 to its uppermit the holder 26 to assume one of its operative or cutting positions.

Each shaft 117 is the axis of a work holder, and mounted on such shaft is such work holder vwhich comprises, besides said shaft, a

horizontal base 124, a horizontal disk 125, a vertical cam sleeve 126, six segmental, vertical separators or spacers 127, the same number of vertical friction bars 135, a horizontal head 128, and six, long, vertical rods 129 and nuts 192 therefor, together with certain otherv arts an members yet to be described, as i ustrated more particularly in Figs..11 and 11". A ball-bearing 130 is interposed between the turn-table 112 and the base 124, so that the latter may revolve freely on the former. The cam sleeve 126 has a\wormwheel 131 While in neutral position positionl beneath the head 122, and to secured to the base thereof, and said sleeve is shouldered vat 132 to receive beneath the shoulder the edge of the opening in the plate 125 provided for the passage of that portion of the sleeve which is between said shoulder and the worm-wheel 131. The wormwheel 131 is received and operates in a central opening 133 in the top of the base 124. Also in said opening is a worm 134 which intermeshes with the worm-wheel 131. The plate 125 rests on the base 124 'above the worm-wheel 131, and the separators 127 and friction bars 135 rest at their lower ends on said plate. The head 128 is on top of the cam sleeve 12f6and the spacers 127. Each separator has two radical arms 136, and one of the rods 129 is located between such arms, and there are top and bottom, horizontal flanges or webs 137 and anintermediate, horizontal angeor web 138 which extend between and connect said arms, and through which said rod passes. The rods also pass through a flanged portion of the cap 128 and the plate 125 to be tapped into the base 124. The friction bars 135 are slidingly arranged between the arms 136 of adjacent spacers 127, on the `plate 125 and under the head 128. The work, consisting of a pluralityl or multiplicity of ring-gear blanks 139, is passed over the head 128 and down around the arms 136 and bars135, with the bottommost blank resting on a supporting ring 140 that is secured to the periphery of the disk 125. The blanlm 139, after being piled or stacked one on top of the other around aligned and formed into a hollow cylinder which is concentric with the work holder, and frictionally secured by means of the cam sleeve 126, after which clampsv v141, there being. as many of such clamps as there are rods 129, 7are placed in position for the further security of the stack of blanks.

The worm 134 is mounted on a shaft 142 that is journaled at .bothterminals in the base 124, and has at one end a squared head 143, Figs. 3 and 4, to receive a wrench (not shown). Upon revolvingv the worm 134, through worm-wheel 131 is rotated with the cam rotated in the opposite direction. The depth d of the bars 135 is sufcient to enable them to be forced hard against the blanks 139,

the medium of the lshaft 142, the` sleeve 126. Formed on the periphery of the when said bars are actuated outwardly by l the cams .126, and firmly to engage sald blanks on the inside and hold them securely in place, at the same time exactly aligning the bars and disposing the same concentrieinem v.cally with-the 1sleevez126 and its shaft 11?.

i adapted to bear with the bottom edge of its vertical part onv the'uppermost blank 139,

.and with its horizontal part on the flange of the head 123, said horizontal part being slotted at 14510 accommodate one ofthe rods 129 below the upper en d of the same. After the blanks 139 have been stacked to the rel quired height, or until approximately level with the tops of the spacers 127, the clamps 141 are sli'pped into place beneath the nuts 192011 the rods 129, withthe depending parts of said clamps bearing on the top of the uppermost blank, and said nuts are screwed down tightly onto saidclamps, thus forcing the latter hard againstthe blanks. lnasmuch as the rods 129 are screwed into the base 124, when the nuts, 192 are screwed down tightly, all of the members through 'which said rods pass are securely tied together. The binding force now exertedby the clamps 141 on the blanks 139, added to the frictlonal engagement existing between the bars 135 and said blanks, causes the latter to be so securely and rigidly held in place on their supportin members that any movement of any blank independent of the holder is rendered impossible.

The Harige of the head 128 may be cut away, as shown at 146, to leave a raised rim 147, Figs. 2 and 11, upon which the inner ends of the clamps 141 bear. This construction insures the desired forcible contact of the clamps 141K with the stack of blanks 139 when the nuts 192 are tightened.

After the blanks 139 have been out and they can be removed from their holder, by

'loosening the nuts 192 and removing the clamps 141, and revolving the worm 134 in the direction' to rotate the worm-wheel 131 to the right. The rotation of the. wormwheel 131 to the right, and the consequent rotation in the same direction of the cam sleeve 126, removes the pressure from the inner edges of the bars 135 and loosens said bars sufficiently to enable the completed gears to be lifted oli of the holder.

r1`he arms 136, which form guides for the friction bars 135, fall short of the blanks 139 when the latter are concentrically disposed, while the throw that may be imparted to'said bars by the cams 144 is suflicient to project said bars beyond the inner circumference of said blanks.

After the blanks 139 have been placed in position on their holder and clamped thereon and thereto, it is necessary to supply the upper end of the shaft 117 of such holder with a bearing, wherefore a horizontal, vertically-movable yoke 148 -is provided. There are two yokes 148, and with each is incorporated the indexing mechanism for the holder and its blanks below. Such mechanism consists in part of a disk 149 having an upwardly-extending sleeve 150. The disk 149'and its sleeve are bored to tit the upper terminal of the shaft 117, and said sleeve is screw-threaded at the top to receivea nut 151. rlihe disk 149 when in operative position rests onthe head 128. 'llhe central portion or hub of the yoke 143 is embraced between the nut 151 above and a ball-bearing 152 below, which latter is interposed between the disk 149 and said hub. rlhe disk A149 is, therefore, free to rotate beneath the hub of the yoke 148 and on or with the shaft 117. The above-mentioned parts and meinbers can be seen to good advantage in Figs.

1,2, s, i, 11, and 1a.

ln the present example the shafts 117 are loosely journaled and thus able to rotate, and the parts and members mounted directly on said shafts are free thereon so that independent movement between them and the shafts is possible, but it is obvious that said shafts .threaded terminals atl the top. rliapered openings, one of which appears at 155 in Fig. 12, are provided in the index disk 149 to receive the protruding portions of the studs 154. Nuts-170, Figs. 3 and 4, are screwed onto the studs 154 above the disk 149. It is now clear that rotary motion imparted to the disk 149 must be communicated to the head 128 and rigidly attached parts and members, including the blanks 139.

Referring more particularly to Figs. 2, 3, and 4, it will be seen that forwardlyand rearwardly-extending wings 156 are provided on oblique webs at opposite ends of the uprights 2, and that these Wings, together with gibs 15T-157 which are bolted to the faces of said wings, afford verticall ways or guides for the inner terminals of the arms of the yokes 148, such terminals of the lefthand yoke being indicated at 158-158 .in Fig. 2, and there appearing also in this view vertical, V-shaped guides 159-159 that fit and slide in corresponding grooves in said wings. Y

Each yoke 148 is counterweighted. Two

cables 160 are attached at their lower terj minals to the arms of the yoke. and counterweights 161-161 are attached to the other Aterminals of said cables, the latter passing over idlers 162--162 that are loosely mounted on horizontal studs 163-163 supported at the proper angles by bearings 164-164 which project from the outer faces of the uprights 2 adjacent to their vertical l ed es at one end or the other. The counterweights 161 enable the yoke 148 to be moved up and down with the application of comparatively little power.

Onl the inner face of that portion of the rear yoke arm that slides between the rear wing 156 and the rear gib 157 a vertlcal rack 165 is provided, and a short shaft 166 is journaled in the back edge of said wing, and has secured thereon a pinion 167 which intermeshes with said rack, Fig. 2. A crank 168 is secured to the rear terminal of the shaft 166, which terminal extends rearwardly beyond the back wing 156. These parts and members are at the left-hand end of the machine behind. and duplicate parts and members are at the other' end of the machine in front, as shown in Fig. 3. When the crank 168 is turned in one direction, the

oke 148 is elevated, through the medium of the shaft 166, pinion 167 and rack 165, and when said crank is turned in the opposite direction said yoke is lowered, through the i same medium as before.

In order to lock each yoke at any desired elevation, or secure the same against possible accidental descent, a lock-screw 169 is tapped into the outer face of the rear (or the front) gib 157 and adapted to bear with its inner terminal against the corresponding face of the adjacent yoke terminal 158. This lock-screw is provided with the usual handle. When the lock-screw 169 is turned inwardly to bear forcibly against the yoke terminal 158, it prevents the yoke from moving downwardly, but upon loosening said screw the yoke may be freely moved in either direction.A The two lock-screws 169 appear in Figs. 1, 2, 3, and 4.

After the blanks 139.have been placed in position on and secured to the holder, the yoke 148 with the index mechanism :for said holder is let down,by means of the pinion 167 and rack 165, over the shaft 117 and onto the head 128 of said holder, said shaft being received in the disk 149 and its sleeve 150. At this time it may be necessary partially to rotate the disk 149 so as to bring the openings 155 in said disk into line with the studs 154 below, in order that, as the yoke descends, said studs .shall enter said openings and permit said disk to come to rest on top of the head 128. Two of the nuts 17 0 are then screwed onto the studs 154 above the disk 149. After the yoke has been lowered into operative positlon, it is secured by means of the lock-screw 169.

After the blanks 139 have been broached and converted into gears, the nuts 170 are taken off, the lock-screw 169 is loosened, and the yoke 148 with the index mechanism is raised clear of the holder, upon which said gears are mounted, into the position such as that indicated by dotted lines (for the right-hand yoke) in Fig. 3. The turntable 112 is then operated to move the aforesaid holder from beneath the yoke, and the gears are removed from the holder.-

Although the yoke is in a sense a part of the work holder and also in a sense a part of the index mechanism, it is herein treated as a distinct or independent member, inasv in are shown a fragment of the disk 149,

which is provided with peripheral lock-teeth 171, and a fragment of a ring 172 having on its periphery ratchet-teeth 173 that are set inwardly a little from said lock-teeth, a horizontal arm 174 provided on the rear edge with teeth 175 that are adapted to intermesh with said first-named teeth, and a horizontal pawl 176 having on the left-hand edge near the free terminal thereof teeth 177 that are adapted to engage with said ratchetteeth. The outer terminal of the arm 174 is `pivotally connected at 178 with a bearing boss or lug 179 on the underside of the lefthand yoke 148, and said arm is provided at its inner terminal with a roll 180. The roll 180 is in the path of a cam-block 181 secured to and carried by the adjacent carrier. 16, see Figs. 1, 7, and 12. The cam-block 108 for the left-hand index is attached to the outer face "of the carrier 16 adjacent to the forward gib 18, near the bottom of said carrier, so that, when the latter ascends and as it approaches the end of its upward travel, said cam-block encounters the roll 180 and swings the index arm 174 forwardly on its pivot 179, against the resiliency of a sprin 182 interposed between the front edge 0% said arm and a lug 183 projected inwardly from the front arm of the left-hand yoke near the inner end thereof; and, when said carrier descends and said block passes away from said roll, said index arm is actuated. rearwardly on said pivot by said spring. The teeth 175 are located a. short distance from the pivot 178, and between said teeth and the roll 180 is a vertical stud 184 which is set in the top of said arm. The pawl 17 6 exvtends rearwardly'from the arm 174, and is provided adjacent to its `forward end with a slot 185 to receive thestud 184. A sprin 186 is arranged between the arm 174 an vthe pawl 17 6 in such a manner as to actuate the latter toward the ring 172 and retain the teeth 177 in engagement with the ratchetteeth 173. The ring 172 is let into an annular peripheral chael in the top eil the disk 149, and secured therein to said disk. '.lwo guard rings 187 `are attached to the disk 1419' and ring 172 above 'and below the lock-teeth 171 and the ratchet-teeth 17?, respectively, and extend a short distance beyond said teeth to `protect the same from chips and dirt that might otherwise come y, is

, downwardly into contact with said teeth as the breaches ascend and descend during the cutting operation.

Normallythe stud 18d is somewhat remote from the front end of the slot 185, consequently the rst edect oi the forward movement imparted te the arm 1711, by the cani-block 181, is to withdraw the teeth 17 5 from the lock-teeth 171 and thus unlock the disk 119. Then the stud 184i encounters the front end of the slot 185, and, through the medium of the pawl 176 with its teeth 177,l which latter engage the ratchet-teeth 173, causes the disk 1&9 with the work holder and work below to be partially rotated. rThe movement thus imparted to the disk and work holder is equal to the distance between two adjacent tooth slots cut orto be cut in the blanks 139., vl/l'hen the arml 17d swings backwardly again under the induence of' its spring 182, aiter being released by the carnblock 181, the teeth 17 5 first engage the lockteeth 171 and so cause the disk 14:9 and the work holder and blanks below to be held against further rotation on the axis et said holder, and then the stud 184,- is carried rearwardly away from the iront end of the slot 185 and into contact with the rear end et said slot, and actuates the awl 176 rearwardly, the pawl teeth 177 c licking past the ratchet-teeth 173, until said teeth 177 have made a new engagement with said ratchetteeth in readiness tor the next indexing operation. The slot 185 must be of sucient length to enable the teeth 17 5 te be disengaged entirely from the lockteeth 171, at the time the arm 17 d is swung forward.

The parts and members which make up the right-hand indexing mechanism are in reverse position relative of the parts and members of the indexing mechanism just described.

The complete operation of the machine as a whole, startlng with the arts and members disposed as shown in t e general views, is briey described as follows:

Assuming that the gear la is rotating to the left, the left-hand carrier 16 travels and causes the roughing breaches 105 in the holder 26 mounted in said carrier to cut a vertical channel through the gear blanks 129 on the leit-hand work holder, and at the saine time the right-hand carrier 16 travels upwardly and causes the i finishing breaches 106 in the holder 26 mounted in said last-named carrier to com- -said holder should be caused to assume the during the drst upward neutral position stroke et its nishing breaches.- t the on of the down stroke et the lett-hand cai 16, the holder 26 therein is unlocked, by the withdrawal of the aeeeeiated pin fr0 para tially rotated to the ri ht, throuh medium of the iront rac 29 which is in engagement therewith, and the bottom seg,rn ment 31 which is in the path et said rack, te position the iinishing breaches 126 in said holder in readiness to complete the cl icl or slot just previously out in the blanke when the holder ascends, and relecked bv said pin; and at they end oit the up eti-reke oit' the right-hand carrier 16, the holder 2d therein is unlocked, partially rotated to the right, through the medium ci the rear rack 29 which is in engaoement with said laetf named holder, and ti e bottom segment 31 which is in the path oi said last-named rack, to position in the work plane y--y the roughing breaches 105 with which said last-named holder is equipped, and relocked.. 1n the event the lirst roughing" out has not been made in the blanks carried by the active, right-hand work holder, the lever 63 is operated te move the right-hand segl ments 31 out et their neutral positions, lfore the right-hand carrier 16 arrives end of its upward travel. 'lhe switch aaai 21 is now actuated to bring about the versa] of the gear 1d, 'and the leitli no carrier is caused to ascend and the ri ito hand carrier to descend, whereb the roughing cut made in the left-hand blanks 180 is finished, and a roughing cut is made in the right-hand blanks 139. After the breaches at the left clear the blanks, and as the lett-hand carrier arrives at the upper end of its travel, the holder carrying said blanks is indexed, through the medium oil the left-hand cam-block 181, and the arm 17d, pawl 176, and other associated parte and members et the left-hand indexing mechanism, to present an uncut portion ci? the blanks, separated by the proper distance from the rtlons last cut, for the action of the roughmg breaches with which are asseciated said iinishingFl breaches, at the next descent of their helder. Similarly the righthand blanks are indexed upon the arrival irc 

